This invention relates to an apparatus for discharging bulk material from a storage tank and is of the type which has a vaned impeller wheel disposed above a housing floor which closes off the lower, terminal portion of the storage tank and which has at least one eccentrically arranged discharge opening. The impeller is driven by a stepping mechanism, the ratchet-and-pawl assembly of which is disposed on the impeller shaft underneath the housing floor and includes at least one pawl-actuating member designed as a pressure medium-actuated power cylinder.
Apparatuses of the above-outlined type have the purpose of eliminating material accumulations in the storage tank to thus insure an unimpeded discharge of the bulk material through the discharge openings.
It is known - as disclosed in German (German Democratic Republic) Pat. No. 43,491 - to continuously rotate the impeller wheel.
In U.S. Pat. No. 3,927,774 there is disclosed an apparatus of the above type which is significantly more economical both from the structural and from the operational point of view. As disclosed in this patent, the impeller wheel is driven by means of a stepping mechanism intermittently in the same direction.
In all known apparatuses, however, particularly in those where the discharge opening is arranged eccentrically with respect to the impeller shaft, the danger of the impeller wheel being blocked by the bulk material has not been eliminated.